Some users don't like to speak in voice channels, but still want to participate! By creating a voice linked channel, users who join the voice channel will be able to see and talk in the text channel, and when they leave, they will lose access.
Make sure you have a voice channel, and have created a channel a channel to link it to. Here's what my channels look like.
In the text channel you want linked, run
ch!voicelink <channel name>. I specified "Talk" so I could link it to the Talk channel.
If you don't want your channel to be linked anymore, run
ch!voicelink unlink in the text channel to clear all links.